C'est que les fibres lentes participent dans toutes les reps. C'est la base de la théorie du recrutement : d'abord les lentes puis les rapides.
The exercises were performed in the fixed order of leg press, squat, and knee extension. After warming up:
· The Low-Rep group used their 3-5RM for four sets with 3 min rest between sets and exercises.
· The Intermediate-Rep group used their 9-11RM for three sets with 2 min rest.
· The High-Rep group used their 20-28 RM for two sets with 1 min rest.
During the study, the resistance was progressively increased as subjects were able to perform more reps in order to ensure subjects were always using their true RM for each rep range.
So what happened? Did the type-I fibers increase most in the high-rep group? Did only the type-II fibers hypertrophy in the low rep group? If you believe you must do high reps for type-I fibers to grow and low reps for type-II fibers to grow then that’s exactly what should have happened!
On the other hand, if hypertrophy is a matter of load, and all fibers hypertrophy in response to increasing load, then hypertrophy should go up as load goes up. In other words the group that lifted the heaviest relative weight should have experienced the greatest amount of hypertrophy in ALL fiber types irrespective of the number of reps (within reason). And that is exactly what happened.
Here is a breakdown of the hypertrophy caused by each rep range. [Remember, each group trained to failure regardless of RM used so muscular fatigue was equal between groups.]
High-Rep (20-28RM)
Type-I
· pre = 3894 post = 4297 (10.3% increase)
Type-IIA
· pre = 5217 post = 5633 (8.0% increase)
Type-IIB
· pre = 4564 post = 5181 (13.5% increase)
Med-Rep (9-11RM)
Type-I
· pre = 4155 post = 4701 (13.1% increase)
Type-IIA
· pre = 5238 post = 6090 (16.3% increase)
Type-IIB
· pre = 4556 post = 5798 (27.3% increase)
Low-Rep (3-5RM)
Type-I
· pre = 4869 post = 5475 (12.4% increase)
Type-IIA
· pre = 5615 post = 6903 (22.9% increase)
Type-IIB
· pre = 4926 post = 6171 (25.3% increase)
donc la on voit que meme pour les jambes, les high reps 20-28 n'ont mené à rien pour les fibres I, alors que le lourd meme 3-5 reps a été plus efficace et aussi plus efficace pour les grosses fibres. Encore une fois c'est pas la fatigue qui compte, mais la tension, la génération de force. Si l'étdue portait sur le haut du corps, ca aurait été encore plus net ! Car le haut du corps est plus fast fibers.
alors que le volume :
4x3-5 pour les low reps, soit 12-20 reps au total
versus
2x20-28 pour les high reps, soit 40-56 reps au total
mais meme pour les fibres lentes, rien ne vaut des big weights ! Et si on avait eu un groupes en singles à 10-20x1